Conventional tracking systems are configured to track a moving object in a sequence of images or video. For example, a tracking system may generate an initial model of an object in a first image of the sequence of images automatically or based on a user input indicating the object. The tracking system uses the initial model to track the object in subsequent images of the sequence of images and to determine a location of the object in the subsequent images. One type of tracking system is a non-adaptive tracking system that generates a single model of the object based on the first image and searches the subsequent images for matches to the model. A problem with the non-adaptive tracking system is that when one or more characteristics (e.g., size, illumination, color, orientation, shape, etc.) of the object change in the subsequent images, the non-adaptive tracking system may be unable to account for the changes and may lose track of the object in the subsequent images when the object is sufficiently different from the initial model.
An adaptive tracking system generates a model based on the object in a first image. However, the adaptive tracking system may modify (e.g., update) the model based on the subsequent images. By updating the model, the adaptive tracking system may continue to track the object even if a characteristic of the object changes. However, if the characteristic of the object changes substantially, or if the object is occluded (e.g., is partially or entirely covered or out of view) in the subsequent images, the adaptive tracking system may modify the model based on incorrect information (e.g., the model may be modified based on a different object that is mistaken for the object in a subsequent image). Once the adaptive tracking system has modified the model incorrectly, the adaptive tracking system tracks the incorrect object in the subsequent images, even if the correct object is no longer occluded. Thus, both the non-adaptive tracking system and the adaptive tracking system may have difficulties tracking objects that undergo substantial changes to one or more characteristics or that become temporarily occluded.